staging: rtl8192e: Remove wireless mode WIRELESS_MODE_N_5G

Remove WIRELESS_MODE_N_5G from equations as it is not supported by
hardware and to improve readability.

Signed-off-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
Link: https://lore.kernel.org/r/fdefd4d706493fa3f080550d31eb5bea3f4e1a7e.1679949171.git.philipp.g.hortmann@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>